Normally, a 15-year milestone of any event — as opposed to 10 years or 25 years — would pass with little fanfare. But recent events have made this one a little different.

Just a few weeks ago, federal agents busted up a Michigan-based Christian militia known as the Hutaree that was accused of plotting to kill law enforcement officers. The arrests triggered chatter on the Sunday talk shows about militias, the potential dangers some might pose and, perhaps inevitably, the Oklahoma City bombing.

Nichols has no ties to the Hutaree, or to any other militia, for that matter. But 15 years ago he found himself in the thick of something like the Hutaree case — only far, far bigger.

The bombing of the Alfred P. Murrah Federal Building in Oklahoma City on April 19, 1995, killed 168 people and sent a shock wave of vulnerability across the nation.